A previously disclosed baker's oven comprises a number of stacked oven compartments with individual oven doors at the front. Each level of the oven includes two components with each compartment generally having a turntable onto which baking trays or bread pans or a like can be loaded.
The oven compartments are heated by electric heating elements in the bottom and top of the compartments. The heating elements are formed as single heating units comprising a number of parallel arms connected in series by U-shaped elements. The parallel arms extend from the oven door to the rear of the compartment and are spaced across the width of the oven.
The top and bottom heating elements can be separately controlled to vary the heat distribution within the oven. For certain types of baked goods, it is advantageous to supply the heat predominantly from the bottom of the oven whilst maintaining the oven at a constant temperature.
Steam can be introduced in controlled manner into the oven compartment of the baker's oven to create glazed buns, “split” crusts or bakery products such as bread and rolls. One means of introducing steam into baker's ovens is to use external steam generators and introduce the steam into the oven through a conduit connecting the steam generator to the oven. This method of steam generation requires an additional steam generator and is thought to be inefficient, not only in terms of the overall heat requirements of the baking and steam generation process but an external steam generator uses up valuable bakery space.
In recent years to avoid the need for external steam generators, water has been sprayed into the oven compartments for conversion into steam. This creates problems for designers and manufacturers of baker's ovens in that the heat energy required to convert water into steam must not be so large as to cause the internal temperature in the compartments to drop more than say 5-10° C., or the quality of the finished baked products may be adversely affected.
Secondly, all of the water must be converted into fine steam before it comes into contact with the bakery products, as impingement of even very small water droplets on the surface of the baker products adversely affects the surface appearance thereof.
A further complication has arisen with the adoption of ceramic surfaces, e.g., ceramic tiles, on the oven turntables on which the products are baked. If the steam is sprayed directly at the ceramic surfaces, they will absorb the steam and the quantity of steam available to the baker's products is minimized.
Australian Patents Nos. 666365, 666633 and 669838, all in the name of APV Australian Pty Ltd, all disclose an internal steaming assembly for a baker's oven in which the parallel rods of the lower heating element in the oven compartments are positioned in the vicinity of a ballast bar. Water from a water supply pipe is sprayed onto the heated ballast bar at the front of the oven compartment and the resulting generated steam left to circulate in the oven compartment. Apart from a plate over the section of the ballast bar adjacent the water pipe to prevent splashing, the ballast bar is not covered and is exposed to debris such as product overflow falling from the rotating turntables onto the hot heating rods. This debris bakes onto the heating rods and ballast bars and must be regularly cleaned from the rods and ballast bars for heating efficiency and product quality reasons.
Australian Patent Application No. 2004262443 discloses a heating element fixed to an elongate steam generation chamber for more effectively generating steam. The contents of Australian Patent Application No. 2004262443 are herein incorporated by a reference.
It has been discovered that, particularly during the early stages of baking when the baking trays are relatively cool, steam from the underlying steam generators can impinge on the underside of the baking tray or turntable where it condenses. This results in a loss of effective steam from the oven cavity. This loss of steam has been found to affect the quality of the baked product.
It is an object of the present invention to provide a heating arrangement that improves the heat distribution within a baking oven, improves the steam supply for a baking oven or at least provides alternatives to existing arrangements in the marketplace.